Method of transmitting message at user equipment in wireless communication system and apparatus thereof

ABSTRACT

A method for transmitting a message by a user equipment (UE) in a wireless communication system is disclosed. The method comprises receiving system information including a specific identifier from a network, receiving a request message from the network, and determining whether or not to transmit a response message to the network in response to the request message based on the specific identifier included in the system information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of PCT/KR2012/002013 filed onMar. 21, 2012, which claims priority under 35 U.S.C. 119(e) to U.S.Provisional Application No. 61/471,179 filed on Apr. 3, 2011, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

TECHNICAL FIELD

The present invention relates to a wireless communication system, andmore particularly, to a method of transmitting a message from a userequipment in a wireless communication system and apparatus therefor.

BACKGROUND ART

First of all, in the following description, 3GPP LTE (3rd generationpartnership projecting long term evolution) communication system isschematically explained as an example of a wireless communication systemto which the present invention is applicable.

FIG. 1 is a schematic diagram of E-UMTS network structure as an exampleof a wireless communication system. E-UMTS (evolved universal mobiletelecommunications system) is the system evolved from a conventionalUMTS (universal mobile telecommunications system) and its basicstandardization is progressing by 3GPP. Generally, E-UMTS can be calledLTE (long term evolution) system. For the details of the technicalspecifications of UMTS and E-UMTS, Release 7 and Release 8 of ‘3rdGeneration Partnership Project: Technical Specification Group RadioAccess Network’ can be referred to.

Referring to FIG. 1, E-UMTS consists of a user equipment (UE) 120, basestations (eNode B: eNB) 110 a and 110 b and an access gateway (AG)provided to an end terminal of a network (E-UTRAN) to be connected to anexternal network. The base station is able to simultaneously transmitmulti-data stream for a broadcast service, a multicast service and/or aunicast service.

At least one or more cells exist in one base station. The cell is set toone of bandwidths including 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, 20MHz and the like and then provides an uplink or downlink transmissionservice to a plurality of user equipments. Different cells can be set toprovide different bandwidths, respectively. A base station controls datatransmissions and receptions for a plurality of user equipments. A basestation sends downlink scheduling information on downlink (DL) data toinform a corresponding user equipment of time/frequency region fortransmitting data to the corresponding user equipment, coding, datasize, HARQ (hybrid automatic repeat and request) relevant informationand the like. And, the base station sends uplink scheduling informationon uplink (UL) data to a corresponding user equipment to inform thecorresponding user equipment of time/frequency region available for thecorresponding user equipment, coding, data size, HARQ relevantinformation and the like. An interface for a user traffic transmissionor a control traffic transmission is usable between base stations. Acore network (CN) can consist of an AG, a network node for userregistration of a user equipment and the like. The AG manages mobilityof the user equipment by a unit of TA (tracking area) including aplurality of cells.

The wireless communication technology has been developed up to LTE basedon WCDMA but the demands and expectations of users and service providersare continuously rising. Since other radio access technologies keepbeing developed, new technological evolution is requested to becomecompetitive in the future. For this, reduction of cost per bit, serviceavailability increase, flexible frequency band use, simple-structure andopen interface, reasonable power consumption of user equipment and thelike are required.

DISCLOSURE OF INVENTION Technical Problem

Based on the above-mentioned discussion, a method of transmitting amessage from a user equipment in a wireless communication system andapparatus therefore shall be proposed in the following description.

Solution to Problem

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a methodfor transmitting a message by a user equipment (UE) in a wirelesscommunication system comprises receiving system information including aspecific identifier from a network; receiving a request message from thenetwork; and determining whether or not to transmit a response messageto the network in response to the request message based on the specificidentifier included in the system information.

Preferably, the method further comprises transmitting the responsemessage to the network if the specific network identifier is an identityof R-PLMN (Registered-Public Land Mobile Network). Here, the requestmessage includes at least one of services that the UE is receiving orinterested to receive. Further, the system information is receivedthrough a first cell of the network, and the response message istransmitted through a second cell of the network.

More preferably, the determining step is performed while the UE is in anRRC (radio resource control) connected mode. Further, the requestmessage comprises an MBMS (multimedia broadcast multicast service)counting request message and the response message comprises an MBMScounting response message

In another aspect of the present invention, a method for receiving amessage by a network in a wireless communication system comprisestransmitting system information including a specific identifier to atleast one user equipment (UE); transmitting a request message to the atleast one UE; and receiving at least one response message from the atleast one UE in response to the request message, the at least oneresponse message being transmitted based on the specific identifierincluded in the system information.

Preferably, the specific identifier is a network identifier. Morespecifically, the specific network identifier is an identity of R-PLMN(Registered-Public Land Mobile Network).

Advantageous Effects of Invention

According to an embodiment of the present invention, a base station isable to provide an effective MBMS to a user equipment.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims thereof as well as the appended drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of E-UMTS network structure as an exampleof a mobile communication system.

FIG. 2 is a conceptional diagram of a network structure of E-UTRAN(evolved universal terrestrial radio access network).

FIG. 3 is a diagram of structures of control and user planes of a radiointerface protocol between a user equipment and E-UTRAN based on 3GPPradio access network specification.

FIG. 4 is a diagram for explaining physical channels used for 3GPPsystem and a general method of transmitting a signal using the same.

FIG. 5 is a diagram for an example of a structure of a radio frame usedfor LTE system.

FIG. 6 is a diagram for explaining a general transceiving method using apaging message.

FIG. 7 is a diagram for a transmission scheme of MCCH (MBMS controlchannel).

FIG. 8 is a flowchart showing a conventional MBMS counting procedure.

FIG. 9 is diagram for explaining problems which may be generated in theconventional MBMS counting procedure.

FIG. 10 is a flowchart showing an MBMS counting response messagetransmission scheme of a UE according to the present invention.

FIG. 11 is an exemplary block diagram of a communication apparatusaccording to one embodiment of the present invention.

MODE FOR THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The embodiments described in the following description includethe examples showing that the technical features of the presentinvention are applied to 3GPP system.

Although an embodiment of the present invention is exemplarily describedin the present specification using the LTE system and the LTE-A system,the embodiment of the present invention is also applicable to any kindsof communication systems corresponding to the above definitions.Although an embodiment of the present invention is exemplarily describedwith reference to FDD scheme in the present specification, theembodiment of the present invention is easily modifiable and applicableto H-FDD or TDD scheme.

FIG. 2 is a conceptional diagram of a network structure of E-UTRAN(evolved universal terrestrial radio access network). In particular, theE-UTRAN system is the system evolved from a conventional UTRAN system.The E-UTRAN includes cells (e.g., eNBs). And, the cells are connectedvia an X2 interface with each other Each of the cell is connected to auser equipment via a radio interface and is also connected to an evolvedpacket core (EPC) via an S1 interface.

The EPC includes MME (Mobility Management Entity), S-GW(Serving-Gateway) and PDN-GW (Packet Data Network-Gateway). The MME hasan information of a user equipment or an information on capability ofthe user equipment. Such information is mainly used for management ofmobility of the user equipment. The S-GW is a gateway having the E-UTRANas a terminal end point. And, the PDN-GW is a gateway having a packetdata network (PDN) as a terminal end point.

FIG. 3 is a diagram of structures of control and user planes of a radiointerface protocol between a user equipment and E-UTRAN based on 3GPPradio access network specification. First of all, a control plane meansa passage for transmitting control messages used by a user equipment anda network to mange a call. A user plane means a passage for transmittingsuch data generated from an application layer as voice data, internetpacket data and the like.

A physical layer, i.e., a first layer, provides an information transferservice to an upper layer using a physical channel. The physical layeris connected to a medium access control layer located above via atransport channel. Data are transferred between the medium accesscontrol layer and the physical layer via the transport channel. Data aretransferred between a physical layer of a transmitting side and aphysical layer of a receiving side via a physical channel. The physicalchannel uses time and frequency as radio resources. In particular, aphysical layer is modulated in downlink by OFDMA (orthogonal frequencydivision multiple access) scheme and is modulated in uplink by SC-FDMA(single carrier frequency division multiple access) scheme.

A medium access control (hereinafter abbreviated MAC) layer of a secondlayer provides a service to a radio link control (hereinafterabbreviated RLC) layer of an upper layer via a logical channel. The RLClayer of the second layer supports reliable data transfer. A function ofthe RLC layer can be implemented using a function block within the MAC.A packet data convergence protocol (hereinafter abbreviated PDCP) layerof the second layer performs a header compression function for reducingunnecessary control information to transmit such an IP packet as IPv4and IPv6 in a radio interface having a narrow bandwidth.

A radio resource control (hereinafter abbreviated RRC) layer located ona lowest level of a third layer is defined in a control plane only. TheRRC layer is responsible for controlling logical channel, transportchannel and physical channels in association with configuration,reconfiguration and release of radio bearers (RBs). In this case, the RBmeans a service provided by the second layer for a data transfer betweena user equipment and a network. For this, the RRC layer of the userequipment exchanges RRC messages with the RRC layer of the network.

One cell, which constructs a base station (eNB), is set to one ofbandwidths including 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHzand the like and then provides an uplink or downlink transmissionservice to a plurality of user equipments. Different cells can be set toprovide different bandwidths, respectively.

A downlink transport channel for transporting data to a user equipmentfrom a network includes a broadcast channel (BCH) for transportingsystem information, a paging channel (PCH) for transmitting a pagingmessage, a downlink shared channel (SCH) for transmitting a user trafficor a control message or the like. A traffic or control message of adownlink multicast or broadcast service can be transmitted via adownlink SCH or a separate downlink multicast channel (MCH).

Meanwhile, an uplink transport channel for transmitting data from a userequipment to a network includes a random access channel for transmittingan initial control message, an uplink shared channel (SCH) fortransmitting a user traffic or a control message or the like. A logicalchannel located above a transport channel to be mapped by a transportchannel includes BCCH (Broadcast Control Channel), PCCH (Paging ControlChannel), CCCH (Common Control Channel), MCCH (Multicast ControlChannel), MTCH (Multicast Traffic Channel) or the like.

FIG. 4 is a diagram for explaining physical channels used for 3GPPsystem and a general method of transmitting a signal using the same.

If a power of a user equipment is turned on or the user equipment entersa new cell, the user equipment performs an initial cell search formatching synchronization with a base station and the like [S401]. Forthis, the user equipment receives a primary synchronization channel(P-SCH) and a secondary synchronization channel (S-SCH) from the basestation, matches synchronization with the base station and then obtainsinformation such as a cell ID and the like. Subsequently, the userequipment receives a physical broadcast channel from the base stationand is then able to obtain intra-cell broadcast information. Meanwhile,the user equipment receives a downlink reference signal (DL RS) in theinitial cell searching step and is then able to check a downlink channelstatus.

Having completed the initial cell search, the user equipment receives aphysical downlink control channel (PDCCH) and a physical downlink sharedcontrol channel (PDSCH) according to information carried on the physicaldownlink control channel (PDCCH) and is then able to obtain systeminformation in further detail [S402].

Meanwhile, if the user equipment initially accesses the base station orfails to have a radio resource for signal transmission, the userequipment is able to perform a random access procedure (RACH) on thebase station [S403 to S406]. For this, the user equipment transmits aspecific sequence as a preamble via a physical random access channel(PRACH) [S403] and is then able to receive a response message via PDCCHand a corresponding PDSCH in response to the preamble [S404]. In case ofcontention based RACH, it is able to perform a contention resolutionprocedure in addition.

Having performed the above mentioned procedures, the user equipment isable to perform PDCCH/PDSCH reception [S407] and PUSCH/PUCCH (physicaluplink shared channel/physical uplink control channel) transmission[S408] as a general uplink/downlink signal transmission procedure. Inparticular, the user equipment receives a downlink control information(DCI) via PDCCH. In this case, the DCI includes such control informationas resource allocation information on a user equipment and can differ informat in accordance with the purpose of its use.

Meanwhile, control information transmitted/received in uplink/downlinkto/from the base station by the user equipment includes ACK/NACK signal,CQI (channel quality indicator), PMI (precoding matrix index), RI (rankindicator) and the like. In case of the 3GPP LTE system, the userequipment is able to transmit the above mentioned control informationsuch as CQI, PMI, RI and the like via PUSCH and/or PUCCH.

FIG. 5 is a diagram for an example of a structure of a radio frame usedfor LTE system.

Referring to FIG. 5, a radio frame has a length of 10 ms (327200×Ts) andis constructed with 10 subframes in equal size. Each of the subframeshas a length of 1 ms and is constructed with two slots. Each of theslots has a length of 0.5 ms (15360×Ts). In this case, Ts indicates asampling time and is expressed as Ts=1/(15 kHz×2048)=3.2552×10⁻⁸ (about33 ns). The slot includes a plurality of OFDM symbols in a time domainand includes a plurality of resource blocks (RB) in a frequency domain.In the LTE system, one resource block includes ‘12 subcarriers×7 or 6OFDM symbols’. A transmission time interval (TTI), which is a unit timefor transmitting data, can be determined by at least one subframe unit.The above described structure of the radio frame is just exemplary. And,the number of subframes included in a radio frame, the number of slotsincluded in a subframe and/or the number of OFDM symbols included in aslot can be modified in various ways.

In the following description, an RRC state of a user equipment and acorresponding RRC connecting method are explained. In this case, the RRCstate means whether an RRC of a user equipment is logically connected toan RRC of E-UTRAN (i.e., logical connection). If the RRCs are connectedto each other, it is called an RRC connected state (RRC_CONNECTED). Ifthe RRCs are not connected to each other, it can be called an RRC idlestate (RRC_IDLE).

Since E-UTRAN is able to obtain an existence of a user equipment in anRRC connected state by a cell unit, it is able to effectively controlthe user equipment. On the contrary, the E-UTRAN is unable to obtain auser equipment in an idle state by a cell unit and the correspondinguser equipment is managed by a CN by a TA unit that is an area unitgreater than a cell. In particular, in order to receive such a serviceas voice and data from a cell, a user equipment in an RRC idle stateshould make a transition to an RRC connected state.

Specifically, when a user initially turns on a power of a userequipment, the user equipment searches for an appropriate cell and thenstays in an RRC idle state at the corresponding cell. If the userequipment staying in the RRC idle state needs to establish an RRCconnection, it makes a transition to an RRC connected state byperforming an RRC connection establishment process. In particular, ifthe RRC connection needs to be established, it means the case that anuplink data transmission is necessary due to user's call attempt or thelike or the case that a response message needs to be sent in case ofreceiving a paging message from the E-UTRAN.

FIG. 6 is a diagram for explaining a general transceiving method using apaging message.

Referring to FIG. 6, a paging message contains a paging cause and apaging record including a UE identity and the like. When the pagingmessage is received, a user equipment is able to perform a discontinuousreception (DRX) for the purpose of power consumption reduction.

In particular, a network configures several paging occasions (POs) foreach time cycle called a paging DRX cycle to enable a specific userequipment to obtain a paging message by receiving a specific pagingoccasion only. The user equipment does not receive a paging channel in atime except the specific paging occasion and is able to stay in a sleepmode to reduce power consumption. And, one paging occasion correspondsto one TTI.

A base station and a user equipment use a paging indicator (PI) as aspecific value indicating a transmission of a paging message. The basestation defines a specific identity (e.g., paging-radio networktemporary identity: P-RNTI) for a usage of the PI and is then able toinform the user equipment of the paging information transmission. Forinstance, a user equipment wakes up each DRX cycle and then receives onesubframe to recognize a presence or non-presence of a paging message. IfP-RNTI is contained in L1/L2 control channel (PDCCH) of the receivedsubframe, the user equipment is able to recognize that the pagingmessage exists in PDSCH of the corresponding subframe. If a UE identity(e.g., IMSI) of the user equipment is contained in the paging message,the user equipment makes a response (e.g., RRC connection, systeminformation reception, etc.) to the base station and is then able toreceive a service.

In the following description, system information is explained. First ofall, the system information should contain necessary information a userequipment should be aware of to access a base station. Therefore, theuser equipment should receive all system information before accessingthe base station and should have latest system information all the time.Since all user equipments in a cell should be aware of the systeminformation, the base station periodically transmits the systeminformation.

System information can be divided into MIB (Master Information Block),SB (Scheduling Block) and SIB (System Information Block). The MIBenables a user equipment to recognize such a physical configuration of acorresponding cell as a bandwidth and the like. The SB indicates suchtransmission information of SIBs as a transmission cycle and the like.In this case, the SIB is an aggregate of system informations related toeach other. For instance, a specific SIB contains information of aneighbor cell only and another SIB just contains information of a ULradio channel used by a user equipment.

In the following description, MBMS (multimedia broadcast multicastservice) is explained. First of all, MBMS (multimedia broadcastmulticast service) is a kind of a broadcast/multicast service and is theservice for transmitting multimedia data packets to a plurality of userequipments simultaneously. ‘Broadcast/multicast service’ or/MBMS’ usedin the present disclosure can be substituted with such a terminology as‘point-to-multipoint service’, ‘MBS (multicast and broadcast service)’and the like. In the MBMS based on IP multicast, user equipments share aresource required for data packet transmission with each other and thenreceive the same multimedia data. Hence, in case that user equipments ona predetermined level using MBMS exist in the same cell, it is able toraise resource efficiency. Since the MBMS has no relation with an RRCconnected state, a user equipment in an idle state is able to receivethe corresponding service.

A logical channel MCCH (MBMS control channel) or MTCH (MBMS trafficchannel) for MBMS can be mapped to a transport channel MCH (MBMSchannel). The MCCH carries an RRC message containing MBMS related commoncontrol information, while the MTCH carries a traffic of a specific MBMSservice. A single MCCH exists in a single MBSFN (MBMS single frequencynetwork) area to carry the same MBMS information or traffic. In casethat a plurality of MBSFN areas are provided by a single cell, a userequipment may be able to receive a plurality of MCCHs.

FIG. 7 shows a transmission scheme of MCCH information.

Referring to FIG. 7, if an MBMS related RRC message is changed in aspecific MCCH, PDCCH transmits M-RNTI (MBMS-radio network temporaryidentity) and an MCCH indicator indicating a specific MCCH. A userequipment, which supports MBMS, receives the M-RNTI and the MCCHindicator via the PDCCH, recognizes that the MBMS related RRC messagehas been changed, and is then able to receive the specific MCCH. The RRCmessage of the MCCH can be changed each change cycle and is repeatedlybroadcasted each repetitive cycle.

Meanwhile, the MCCH transmits MBSFNAreaConfiguration message thatindicates a ongoing MBMS session and a corresponding RB setting. And,the MCCH is able to transmit an MBMS counting request(MBMSCountingRequest) message for counting the number of user equipmentsin an RRC connected state, each of which receives or intends to receiveat least one MBMS service.

A specific MBMS control information can be provided via BCCH. Inparticular, the specific MBMS control information can be contained inSystemInformationBlockType13 broadcasted via the BCCH.

As described above, the network can count the number of user equipments,each of which receive or intends to receive a specific service, i.e. aspecific MBMS, through an MBMS counting procedure. In a conventionalMBMS counting procedure, if the network transmits an MBMS countingrequest message, the user equipment transmits an MBMS counting responsemessage through a DCCH (dedicated control channel).

FIG. 8 is a flowchart showing a conventional MBMS counting procedure.

Referring to FIG. 8, a base station (eNB) starts a counting procedureaccording to an MBMS counting request from an MCE (MBMS coordinatingentity) and an MBMS counting response corresponding thereto in stepsS801 and S802. The MCE refers to a network entity performing admissioncontrol, radio resource allocation, session control signaling etc. Next,the eNB updates MCCH information according to information included inthe MBMS counting request in step S803.

The eNB broadcasts an MBMS counting request message through an MCCH instep S804. The MBMS counting request message includes an MBMS ID list. Auser equipment which monitors the MCCH in an MBSFN area may receive thecounting request message through the MCCH. If an ID of a service thatthe user equipment intends to receive is included in the countingrequest message, the user equipment transmits an MBMS counting responsemessage to the eNB through a DCCH in step S805.

Finally, the eNB may receive counting response messages for acorresponding service from a plurality of user equipments, counts thenumber of user equipments transmitting the response message and informsthe MCE of an MBMS counting result in step S806.

FIG. 9 is diagram for explaining problems which may be generated in theconventional MBMS counting procedure.

Referring to FIG. 9, if a user equipment which is RRC connected with afirst cell of a first frequency intends to receive an MBMS from a secondcell of a second frequency, the user equipment may receive an MBMScounting request message from an MCCH of the second cell. If an ID ofthe MBMS the user equipment intends to receive is included in thecounting request message, the user equipment transmits an MBMS countingresponse message to the first cell.

Upon receiving the MBMS counting response message, the first celltransmits, if it supports the MBMS, an MBMS counting result to an MCEaccording to the received MBMS counting response message. However, ifthe first cell does not support the MBMS, the first cell disregards thereceived MBMS counting response message. In this case, a problem arisesin that the user equipment has unnecessarily transmitted the MBMScounting response message.

Accordingly, the present invention is devised to solve the problem ofunnecessary transmission of the MBMS counting response message by theuser equipment. To this end, a user equipment, which is registered in aspecific wireless network, i.e. a specific PLMN (public land mobilenetwork) and is connected to a first cell, receives an MBMS countingrequest message from a second cell. If the MBMS counting request messageis associated with the wireless network, the user equipment transmits anMBMS counting response message, and if the MBMS counting request messageis not associated with the wireless network, the user equipment does nottransmit the MBMS counting response message. Here, the first cell may bethe same as or may be different from the second cell. The PLMN refers toa network ID of a mobile communication network provider.

Namely, the user equipment determines whether the MBMS counting requestmessage is associated with the wireless network according to a PLMN IDbroadcast through system information of the second cell. Morespecifically, if the PLMN ID broadcast through the system information ofthe second cell indicates a PLMN registered by the user equipment,(R-PLMN), the user equipment determines whether the MBMS countingrequest message is associated with the wireless network. Desirably, thefirst cell broadcasts the registered PLMN (R-PLMN) through the systeminformation.

FIG. 10 is a flowchart showing an MBMS counting response messagetransmission scheme of a user equipment according to the presentinvention.

Referring to FIG. 10, the user equipment selects a wireless network of aservice provider, i.e. a PLMN and selects a cell corresponding to thePLMN. Next, the user equipment establishes an RRC connection with theselected cell in step S1001 and registers itself in the selected PLMN instep S1002. Afterwards, a NAS layer of the user equipment is in anEMM-REGISTERED state. The PLMN in which the user equipment has beenregistered is referred to as an R-PLMN. The user equipment can performan MBMS counting procedure only in an RRC connection mode. In FIG. 10,it is assumed that the user equipment is RRC connected with a firstcell.

In step S1003, the user equipment receives system information broadcastby the first cell and continues to maintain the latest information. Thesystem information may be broadcast through a BCCH. The first cell maysupport one or more PLMNs and broadcasts PLMN IDs (i.e. PLMN list) ofthe PLMNs supported thereby through system information. In this case,the R-PLMN of the user equipment should be included in the PLMN list.

Meanwhile, if the user equipment connected to the first cell intends toreceive an MBMS broadcast by a second cell, the user equipment monitorssystem information broadcast through the BCCH from the second cell instep S1004. The system information broadcast from the second celldesirably includes PLMN IDs (i.e. PLMN list) supported by the secondcell and MBMS information.

Next, the second cell may perform a counting procedure for the MBMS. Atthis time, the second cell broadcasts an MBMS counting request messagethrough an MCCH in step S1005. The MBMS counting request messageincludes IDs of more than one MBMS.

According to the prior art, upon receiving the MBMS counting requestmessage from the second cell, the user equipment responds to the MBMScounting request message when an ID of an MBMS that the user equipmentintends to receive is included in the MBMS counting request message.However, in the present invention, the user equipment identifies whetheran R-PLMN ID thereof is included in the PLMN list broadcast through thesystem information of the second cell in step S1006. Namely, the userequipment determines to respond to the MBMS counting request messageonly when the R-PLMN ID of the user equipment is broadcast through thesystem information of the second cell or through MCCH information. Here,the MBMS counting request message desirably includes the R-PLMN ID ofthe user equipment.

As a response to the MBMS counting request message, the user equipmenttransmits an MBMS counting response message to the first cell through aDCCH in step S1007.

As is apparent from the foregoing description, the user equipment, whichis registered in a specific wireless network, i.e. a specific PLMN andis connected to the first cell, receives the MBMS counting requestmessage from the second cell. If the MBMS counting request message isassociated with the specific PLMN, the user equipment transmits the MBMScounting response message, and if the MBMS counting request message isnot associated with the specific PLMN, the user equipment does nottransmit the MBMS counting response message. Accordingly, the problemthat the user equipment unnecessarily transmits the MBMS countingresponse message can be solved.

FIG. 11 is an exemplary block diagram of a communication apparatusaccording to one embodiment of the present invention.

Referring to FIG. 11, a communication device 1100 includes a processor1110, a memory 1120, an RF module 1130, a display module 1140 and a userinterface module 1150.

The communication device 1100 is illustrated for clarity and convenienceof the description and some modules can be omitted. Moreover, thecommunication device 1100 is able to further include at least onenecessary module. And, some modules of the communication device 1100 canbe further divided into sub-modules. The processor 1110 is configured toperform operations according to the embodiment of the present inventionexemplarily described with reference to the accompanying drawings. Inparticular, the detailed operations of the processor 1110 can refer tothe contents described with reference to FIGS. 1 to 10.

The memory 1120 is connected to the processor 1110 and stores anoperating system, applications, program codes, data and the like. The RFmodule 1130 is connected to the processor 1110 and performs a functionof converting a baseband signal to a radio signal or converting a radiosignal to a baseband signal. For this, the RF module 1130 performsanalog conversion, amplification, filtering and frequency uplinktransform or inverse processes thereof. The display module 1140 isconnected to the processor 1110 and displays various kinds ofinformations. The display module 1140 can include such a well-knownelement as LCD (Liquid Crystal Display), LED (Light Emitting Diode),OLED (Organic Light Emitting Diode) and the like, by which the presentinvention is non-limited. The user interface module 1150 is connected tothe processor 1110 and can include a combination of well-knowninterfaces including a keypad, a touchscreen and the like.

The above described embodiments correspond to combination of elementsand features of the present invention in prescribed forms. And, it isable to consider that the respective elements or features are selectiveunless they are explicitly mentioned. Each of the elements or featurescan be implemented in a form failing to be combined with other elementsor features. Moreover, it is able to implement an embodiment of thepresent invention by combining elements and/or features together inpart. A sequence of operations explained for each embodiment of thepresent invention can be modified. Some configurations or features ofone embodiment can be included in another embodiment or can besubstituted for corresponding configurations or features of anotherembodiment. It is apparent that an embodiment can be configured bycombining claims, which are not explicitly cited in-between, togetherwithout departing from the spirit and scope of ‘what is claimed is’ orthat those claims can be included as new claims by revision after filingan application.

In the present disclosure, embodiments of the present invention aredescribed centering on the data transmission/reception relations betweena relay node and a base station. In this disclosure, a specificoperation explained as performed by a base station can be performed byan upper node of the base station in some cases. In particular, in anetwork constructed with a plurality of network nodes including a basestation, it is apparent that various operations performed forcommunication with a terminal can be performed by a base station orother network nodes except the base station. In this case, ‘basestation’ can be replaced by such a terminology as a fixed station, aNode B, an eNode B (eNB), an access point and the like.

Embodiments of the present invention can be implemented using variousmeans. For instance, embodiments of the present invention can beimplemented using hardware, firmware, software and/or any combinationsthereof. In case of the implementation by hardware, a method accordingto one embodiment of the present invention can be implemented by atleast one selected from the group consisting of ASICs (applicationspecific integrated circuits), DSPs (digital signal processors), DSPDs(digital signal processing devices), PLDs (programmable logic devices),FPGAs (field programmable gate arrays), processor, controller,microcontroller, microprocessor and the like.

In case of the implementation by firmware or software, a methodaccording to each embodiment of the present invention can be implementedby modules, procedures, and/or functions for performing theabove-explained functions or operations. Software code is stored in amemory unit and is then drivable by a processor. The memory unit isprovided within or outside the processor to exchange data with theprocessor through the various means known in public.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

As mentioned in the foregoing description, although a method for a userequipment to transmit a message in a wireless communication system andapparatus therefore is described mainly with reference to examplesapplied to 3GPP LTE system, the present invention is applicable tovarious kinds of wireless communication systems as well as the 3GPP LTEsystem.

The invention claimed is:
 1. A method of transmitting a message by auser equipment (UE) in a wireless communication system, comprising:receiving a multimedia broadcast multicast service (MBMS) countingrequest message through a first cell of a network; determining whetheror not to transmit a MBMS counting response message in response to theMBMS counting request message; and transmitting the MBMS countingresponse message if it is determined to transmit the MBMS countingresponse message, wherein determining whether or not to transmit theMBMS counting response message comprises determining to transmit theMBMS counting response message if a registered-public land mobilenetwork (R-PLMN) identity is included in system information broadcastedby the network.
 2. The method of claim 1, wherein the system informationis broadcasted by the first cell of the network.
 3. The method of claim2, wherein the MBMS counting response message is transmitted to a secondcell of the network.
 4. The method of claim 1, wherein the determiningstep is performed while the UE is in a radio resource control (RRC)connected mode.
 5. A method of receiving a message by a network in awireless communication system, comprising: transmitting a multimediabroadcast multicast service (MBMS) counting request message through afirst cell of the network to at least one user equipment (UE); andreceiving at least one MBMS counting response message from the at leastone UE, the at least one MBMS counting response message beingtransmitted by the at least one UE if it is determined to transmit theat least one MBMS counting response message in response to the MBMScounting request message, wherein the at least one UE determines totransmit the at least one MBMS counting response message in response tothe MBMS counting request message if a registered-public land mobilenetwork (R-PLMN) identity is included in system information broadcastedby the network.
 6. The method of claim 5, wherein the system informationis broadcasted by the first cell of the network.
 7. The method of claim6, wherein the at least one MBMS counting response message is receivedthrough a second cell of the network.
 8. The method of claim 5, whereinthe at least one UE is in a radio resource control (RRC) connected mode.